A5032459548- Organic Electronics and Photovoltaics
- Robotic Mechanisms and Dynamics
- Conducting polymers and applications
- Structural Analysis and Optimization
- Modular Robots and Swarm Intelligence
- Piezoelectric Actuators and Control
- Molecular Junctions and Nanostructures
- Dynamics and Control of Mechanical Systems
- Iterative Learning Control Systems
- Perovskite Materials and Applications
- Photochemistry and Electron Transfer Studies
- Quantum Dots Synthesis And Properties
- Spectroscopy and Quantum Chemical Studies
- Advanced Materials and Mechanics
- Organic Light-Emitting Diodes Research
- Photoreceptor and optogenetics research
- Semiconductor materials and interfaces
- Fullerene Chemistry and Applications
- Chemical Synthesis and Characterization
- Nuclear Physics and Applications
- Luminescence and Fluorescent Materials
- Chalcogenide Semiconductor Thin Films
- Machine Learning in Materials Science
- Engineering and Materials Science Studies
- Crystallography and molecular interactions
Max Planck Institute for Polymer Research
2020-2024
Yanshan University
2015-2021
Lanzhou University of Technology
2019
University of Stuttgart
2015-2018
University of Tübingen
2018
Chongqing Normal University
2018
Xi'an Medical University
2018
University of Würzburg
2011-2016
University of New Mexico
2014
Johannes Gutenberg University Mainz
2013
Abstract The short exciton diffusion length associated with most classical organic semiconductors used in photovoltaics (5-20 nm) imposes severe limits on the maximum size of donor and acceptor domains within photoactive layer cell. Identifying materials that are able to transport excitons over longer distances can help advancing our understanding lead solar cells higher efficiency. Here, we measure a wide range nonfullerene molecules using two different experimental techniques based...
Femtosecond time-resolved experiments demonstrate that the photoexcited state of perylene tetracarboxylic acid bisimide (PBI) aggregates in solution decays nonradiatively on a time-scale 215 fs. High-level electronic structure calculations dimers point toward importance an excited intermolecular geometry distortion along reaction coordinate induces energy shifts and couplings between various states. Time-dependent wave packet incorporating simple dissipation mechanism indicate fast quenching...
Efficiencies of organic solar cells have practically doubled since the development non-fullerene acceptors (NFAs). However, generic chemical design rules for donor-NFA combinations are still needed. Such proposed by analyzing inhomogeneous electrostatic fields at donor-acceptor interface. It is shown that an acceptor-donor-acceptor molecular architecture, and alignment parallel to interface, results in energy level bending destabilizes charge transfer state, thus promoting its dissociation...
Abstract Persistent luminescence from triplet excitons in organic molecules is rare, as fast non‐radiative deactivation typically dominates over radiative transitions. This work demonstrates that the substitution of a hydrogen atom derivative phenanthroimidazole with an N ‐phenyl ring can substantially stabilize excited state. stabilization converts material without phosphorescence emission into molecular system exhibiting efficient and ultralong afterglow at room temperature. Results...
The reliability of linear response approaches such as time-dependent Hartree-Fock (TD-HF) and density functional theory (TD-DFT) for the prediction excited state properties 3,4;9,10-tetracarboxylic-perylene-bisimide (PBI) aggregates is investigated. A dimer model PBI investigated a function torsional motion monomers, which was shown before to be an important intermolecular coordinate in these aggregates. potential energy curves ground two energetically lowest neutral charge-transfer (CT)...
The exciton diffusion length (LD) is a key parameter for the efficiency of organic optoelectronic devices. Its limitation to nm scale causes need complex bulk-heterojunction solar cells incorporating difficulties in long-term stability and reproducibility. A comprehensive model providing an atomistic understanding processes that limit trasport therefore highly desirable will be proposed here perylene-based materials. Our based on simulations with hybrid approach which combines high-level ab...
Abstract Aggregates of functionalized polycyclic aromatic molecules like perylene derivatives differ in important optoelectronic properties such as absorption and emission spectra or exciton diffusion lengths. Although those differences are well known, it is not fully understood if they caused by variations the geometrical orientation within aggregates, electronic structures dye aggregates interplay both. As this knowledge interest for development materials with optimized functionalities, we...
Abstract Advancing non‐fullerene acceptor (NFA) organic photovoltaics requires the mitigation of efficiency‐limiting processes. Acceptor end‐group and side‐chain engineering are two handles to tune properties, a better understanding their specific impact on photophysics could facilitate more guided design. Here, device performance, energetic landscape, rhodanine dicyanovinyl end‐capped IDT‐based NFAs, namely, O‐IDTBR O‐IDTBCN, in PCE10‐based solar cells compared by transient optical...
Abstract Bimolecular charge recombination is one of the most important loss processes in organic solar cells. However, bimolecular rate cells based on novel non-fullerene acceptors mostly unclear. Moreover, origin reduced-Langevin bulk heterojunction general still poorly understood. Here, we investigate and transport a series high-performance acceptors. From steady-state dark injection measurements drift–diffusion simulations current–voltage characteristics under illumination, Langevin...
Abstract In organic semiconductors, a donor/acceptor heterojunction is typically required for efficient dissociation of excitons. Using transient absorption spectroscopy to study the dynamics excited states in non‐fullerene acceptors (NFAs), it shown that NFAs can generate charges without interface. This due fact dielectric solvation provides driving force sufficient dissociate state and form charge‐transfer (CT) state. The CT further dissociated into free at interfaces between...
Nickel oxide (NiO) is a widely used material for efficient hole extraction in optoelectronic devices. However, its surface characteristics strongly depend on the processing history and exposure to adsorbates. To achieve controllability of electronic chemical properties solution-processed nickel (sNiO), we functionalize with self-assembled monolayer (SAM) 4-cyanophenylphosphonic acid. A detailed analysis infrared photoelectron spectroscopy shows chemisorption molecules nominal layer thickness...
We present a general method for analyzing the character of singly excited states in terms charge transfer (CT) and locally (LE) configurations. The analysis is formulated configuration interaction singles (CIS) wave functions aggregate systems. It also approximately works second-order approximate coupled cluster doubles algebraic-diagrammatic construction methods [CC2 ADC(2)]. not only generates weight each an state, but allows to define related quasi-diabatic corresponding coupling matrix...
Although there is an agreement about the local structural order of semiconducting polymers such as poly(3-hexylthiophene) (P3HT), still a debate over impact molecular doping. One prevalent interpretation that dopant molecules intercalate in π–π stacking crystallites; however, this idea has recently been challenged. We present here electron diffraction measurements P3HT doped with two dopants 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and molybdenum...
In the deployable mechanism for a conventional truss antenna, nodes cannot be adjusted to uniform in attitude. To solve this problem, method of adding constraint chains is proposed based on reciprocal screw theory. By performing type synthesis mechanisms novel developed that not only enables complete folding and unfolding but also allows attitude made uniform. First, according unit division antenna reflection surface characteristic motions nodes, can added between two adjacent are...
Space deployable structures with large calibers, high accuracy, and folding ratios are indispensable equipment in the aerospace field. Given that single-DOF 3RR-3RRR unit cannot be fully folded, this study proposes a 3UU-3URU two kinds of DOF: movement orientation adjustment. First, based on G-K formula, DOF is analyzed. Then, used to construct truss antenna curved surface, whole containing multiple units calculated. The structural design loops carried out specific parameters geometric...
Theoretical description of electronically excited states molecular aggregates at an ab initio level is computationally demanding. To reduce the computational cost, we propose a model Hamiltonian approach that approximates state wavefunction aggregate. We benchmark our on thiophene hexamer, as well calculate absorption spectra several crystalline non-fullerene acceptors, including Y6 and ITIC, which are known for their high power conversion efficiency in organic solar cells. The method...
Abstract Recently, the truss antennas with deployable tetrahedron unit mechanisms have been successfully applied in orbit, owing to advantages of large calibers, high accuracy, and folding ratios. As multiloop coupled mechanisms, tetrahedral multiple different output links, whose supporting limbs connecting links base are mutually coupled. These also called passive-input overconstrained because their passive torsion springs used as drivers number contained is more than degrees freedom...
Reducing voltage losses while maintaining high photocurrents is the holy grail of current research on non-fullerene acceptor (NFA) based organic solar cell. Recent focus lies in understanding various fundamental mechanisms blends with minimal energy offsets - particularly relationship between ionization offset (ΔIE) and free charge generation. Here, we quantitatively probe this multiple NFA-based by mixing Y-series NFAs PM6 different molecular weights, covering a broad power conversion...
On the example of an aggregate two perylenebisimide (PBI) molecules character lowest excited electronic states in terms charge transfer (CT) and Frenkel exciton (FE) configurations is investigated as a function intermolecular arrangement. A minimal model Hamiltonian based on FE CT at frontier-orbitals CIS (FOCIS) level shown to represent simple comprehensible approach providing insight into physical significance matrix elements. The recently introduced analysis diabatization procedure (Liu...
To tune the efficiency of organic semiconductor devices it is important to understand limiting factors as trapping mechanisms for excitons or charges. An understanding such deserves an accurate description involved electronical states in given environment. In this study, we investigate how a polarizable surrounding influences relative positions electronically excited dimers different perylene dyes. Polarization effects are particularly interesting these systems, because gas phase...